What defines the arrangement of amino acids in a protein?

The arrangement of amino acids in a protein is defined by genetic coding. Genes, made of DNA, contain the instructions for synthesizing proteins through a process of transcription and translation. During transcription, a specific segment of DNA is copied into messenger RNA (mRNA), and during translation, the mRNA sequence is read by ribosomes to assemble amino acids into a polypeptide chain based on the codon sequence. Each set of three nucleotides in mRNA corresponds to one amino acid, which determines the primary structure of the resulting protein. This genetic code is universal across all living organisms and plays a critical role in the precise sequencing of amino acids, ultimately influencing the protein's structure and function.